Question

What is the sequence of events taking place in the plantar reflex, naming the sensory and motor neurons, and the muscles involved in this reflex.

Answer 1

Ans :

Plantar reflex :  An extensor plantar response may be obtained in the absence of damage to the pyramidal tract due to possible dissociation of the nerve fibres in the spinal reflex arc, with excitation of the distal motor neurons and inhibition of the impulses via flexor reflex afferent nerve fibres, since they are mediated by different

Pathways

Afferent: Nociception detected in the S1 dermatome and travels up the tibial nerve to the sciatic nerve to roots of L5,S1 and synapse in the anterior horn to elicit the motor response.

Efferent: Motor response back through the L5,S1 roots to the sciatic nerve to its bifurcation. Toe flexors are innervated by the tibial nerve. Toe extensors (extensor hallucis longus, extensor digitorum longus) are innervated by the deep peroneal nerve. Loss of normal adult descending pyramidal control of the reflex arc to suppress extensor withdrawal results in the upgoing toes in the plantar reflex known as Babinski's sign.

Muscles involved :  The muscles taking part in a fully developed response include the extensor hallucis longus, tibialis anterior, extensor digitorum longus, hamstring group of muscles, and the tensor fasciae latae